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Ductile Iron Pipe Coatings

Svobodny Sokol ductile iron pipes DN 80-1000 mm are produced 6 meters long in complex with rubber gasket and with internal lining and external ptotective coatings according to All Union State Standard R (Russian national standard (ГОСТ)), ISO 2531, EN 545, EN 598.

Outside coating 

Internal Lining

The outside coating of the ductile iron pipes is apllied in oder to rotect the pipe from corrosion soil agression and the exist ground currents. 

A standard zinc covering is an active cause of the galvanic interracting of the zinc-ductile reaction. The defending mechanism has a double effect: when zinc contacts the soil a new layer is formed of the zinc salts. In case of the local damage the layer regenerates. 

Depending on the working conditon the outer coating can be applied in different combinations:

  • Metal zinc + finishing layer according to ISO 8179-1

  • Zinc-alumina + finishing layer according to ISO 8179-1

  • Without any or all the coverings according to customer's desire

The outside surface of the ductile iron pipe can be covered with the finishing layer of:

  • Paint based on synthetic resin

  • Epoxy  

  • Bituminous paint

The inner surface of the ductile iron pipe is covered with the cement-mortar lining. The peculiarity of this type of lining is that it provides a passive and an active protection effect. The passive effect is reached because of the isolation of the water from the pipe metal surface. 

An active one is that an additional layer of the lining apears and protect the pipe surface from possible corrosion. 

Except for the protection layer cement-mortar lining makes the hydraulic properties of the pipeline better because of the internal corrosion and any formation absence and because of a thin layer appearance on the lining surface.

Ductile iron pipes with the cement mortar lining allow to decrease hydraulic losts and corresponds to any basic requirenments in the field of energy effectiveness.   

For pipeline internal protection can be used the lining based on portland-cement, sulphate -resistant cement and high-alumina cement depending on aggressive liquid transportation influence 

The choice of the internal lining should be considered according to EN 545 an EN 598 standards.

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